Barnum the musical traces Phineas Taylor Barnum's career from 1835 to 1881 when he joined James A. Bailey to form the circus which was called The Greatest Show on Earth. Barnum is a defender of "the noble art of humbug" with a philosophy, and has a free wheeling ambition to make a fortune. He buys the oldest woman in the world, named Joyce Heath, as a sideshow attraction. Barnum builds a museum of curiosities supported by his wife Charity, who would like him to settle down.

In 1846, Anthony Hope sails into London with the mysterious Sweeney Todd, a once-naive barber whose life and marriage was uprooted by a corrupt justice system. Todd confides in Nellie Lovett, the owner of a local meat pie shop, and the two become partners, as Todd swears revenge on those that have wronged him and decides to take up his old profession.